Download SACA C-202 ELECTRIC MOTOR CONTROL SYSTEMS FINAL PAPER 2026 EXAM and more Exams Nursing in PDF only on Docsity!
SACA C-202 ELECTRIC MOTOR CONTROL
SYSTEMS FINAL PAPER 2026 EXAM
โ The selector switch is controlled by ____ the push button sleeve. Answer: turning โ Mechanically held relays are often used in machine tool control circuits. Answer: true โ Why are contactors described as both control pilot devices and large magnetic switches controlled by pilot devices? Answer: Large contactors may be controlled by relays. b. Because of the range in sizes available. c. All answers are correct.(Correct Answer) d. While large contactors can control heavy currents where overload protection is unnecessary or provided separately. e. Small contactors may be used as control devices for larger controls. โ When a motor must be started and stopped from more than one location, ____. Answer: any number of start and stop buttons may be connected
โ Why will the blowout coil also operate on AC Answer: Since the current reverses simultaneously in the blowout coil and arc, the motor action (arc deflection) occurs in the same direction. โ Are "ON" control stations used in multiple locations connected in series or parallel for latched-in contactors? Answer: Only for parallel connections for "ON" not for "OFF" โ Timing Relays can come equipped with timing contacts and instantaneous contacts. Answer: true โ It is desirable to extinguish the arc as quickly as possible to keep the contacts cool and this prolong contact life Answer: true โ Schematics show components in their electrical sequence without regard for __. Answer: physical location โ The principal difference between a contactor and a motor starter it that a motor starter contains overload relays and a contactor does not. Answer: true โ A circle is most often used to represent a coil in a motor control schematic, because the letters and/or numbers are written in the circle to identify the coil. Answer: true
โ Is the pneumatic timer the most commonly used in industrial applications? Answer: true โ The neutral wire can be_______. Answer: White and Light Grey โ How many wires are required for a two-wire control device? Answer: 2 โ Magnetic relays are affected by the electricnoise and the voltage spikes induced in the system Answer: false โ Neither jogging nor inching prevent a holding circuit. Answer: false โ Electronic timers have become increasinglypopular in industrial applications. Answer: true โ A power transistor is used to connect the load to the line in a solid-state relay intended to control a DC load. Answer: true โ When the load side of the circuit is separated from the control side by a light beam it is called optoisolation Answer: true โ Start buttons are electrically wired in series. Answer: false
โ What will happen if the terminals of a blowout coil are reversed? Answer: Theoretically, the motor action of the arc will be in the opposite direction. โ Multiple stop buttons are electrically wired in _________ Answer: series โ Main or subassembly line conveyors use sequence control. Answer: true โ The operation of the overload protection ____ the control circuit. Answer: opens โ You should never wire in a set of normally closed contacts in a series with thecoil of the same device. Answer: true โ The larger contactor sizes are used to provide remote control of relatively high-current circuits where it is too expensive to run the power leads to the remote controlling location Answer: true โ What does IEC stand for? Answer: International Electrotechnical Commission
โ Select the definition of a schematic diagram. (Be thorough!!! Answer: Shows the sequence of operation of equipment. โ Sequence control exists when starters are connected so that one cannot be started until the other is energized Answer: true โ Timing relays are used for any application wherethe operating sequence requires a delay Answer: true โ Single-pole and double-pole switch symbols are shown as. Answer: single break. b. double break c. all of the above(Correct Answer) d. NO and NC โ What is the safety feature of a lock-stop push button? Answer: both answers are correct โ Control magnetic relays are used to controlsmall loads Answer: true โ The symbol for a __ switch represents a bimetal helix. Answer: temperature
โ The addition of a control relay to a jogging circuit provides even greater control of the motor drive than the use of a jogging circuit alone. Answer: true โ It is sometimes desirable to operate push buttons or other control devices at some voltage higher than the motor voltage Answer: false โ The equipment ground can be _______. Answer: green and bare โ A control relay is an electrically operated switch. Answer: true โ What type of device is used to suppress voltage spikes in relay circuits? Answer: Transient suppressor or Metal oxide varistor โ Three-wire control prevents the restarting of machinery when power is restored. Answer: true โ Timed contacts are either normally open or normally closed Answer: true โ Typical control voltages are 120 and ____ volts Answer: 24
โ Sequence control is required whenever the ____ must be operating before the machine itself can be operated safely. Answer: auxiliary equipment associated with a machine โ The motor action established by the magnetic fields of the blowout coil and the arc plus the use of arc deflectors or arcing horns cause the arc to Lengthen and move upward. Answer: true โ If set in the ____ position, the coil is connected directly to the power line and the motor will run continuously. Answer: on โ Pilot lights are tested frequently to ensure operation Answer: true โ 24 volts is the most common control voltage used in an intrinsically safe system Answer: true โ A three-wire control circuit uses momentary contact, start-stop stations, and a holding circuit interlock connected ____ with the start button to maintain the circuit Answer: in parallel โ What conductor can be any color except white, light gray, green or bare? Answer: hot
โ The conventional three-wire, push-button control circuit may be extended by the addition of one or more push-button control stations. Answer: true โ Ladder diagrams are sometimes referred to as elementary diagrams Answer: true โ The greatest advantage of relays with mechanicalcontacts is that they are resistant to shock and vibration Answer: false โ The term inching is often used when referring to across-the-line starters. Answer: false โ Jogging is defined by ____ as "the quickly repeated closure of a circuit to start a motor from rest for the purpose of accomplishing small movements of the driven machine." Answer: nema โ When components are used to perform the function of stop, they are generally wired ____ with the motor starter coil. Answer: n ormally closed and connected in series โ The motor may be started or stopped from a number of separate stations by connecting all start buttons in parallel and ____ stop buttons in series. Answer: all
โ A flow switch is classified as a pilot device. Answer: true โ Which of the following are factors to be considered when selecting a timing relay for a particular use. a. Allowable error b. Length of time delay required c. Timing range required d. Cycle of operation and reset time e. Cost f. Additional requirements (electrical rating, size, temperature) Answer: all of them โ In the case of a(n) ____, the thermal heaters open the overload contacts in the control circuit and de-energize the coil, thus stopping the motor. Answer: overload โ In a three-wire control circuit, when the supply voltage returns after a failure, the circuit is re-energized. Answer: false โ Another name for a schematic diagram is an elementary diagram Answer: true โ Relays are used more often to open and closecontrol circuits than to operate power circuits. Answer: true
โ When a jogging circuit is used, the starter can be energized only as long as the jog button is depressed Answer: true โ Control relays are small magnetic switches used on simple branch circuits to control complex wiring system operations. Answer: true โ When the switch is set in the hand position, contacts 1 and 2 are closed, and contacts 3 and 4 are ____. Answer: open โ Schematics are always drawn to show components in their de- energized or off state Answer: true โ A hand-off automatic switch may be a stand alone control or incorporated into a start-stop push button station. Answer: true โ If the available power is 480/277-3 phase, and the control circuit is wired fromphase to ground, what is the control voltage? _____ volts Answer: 277 โ Starters, contactors, and ____ are similar in construction and operation Answer: relays โ No-voltage protection protects ____. Answer: both the operator and the equipment
โ A "C" on an HOA switch indicates that the contacts are closed and the O indicates that they are open. Answer: false โ Electrical symbols are shown in the de-energized position on Schematic diagrams Answer: true โ Two-wire control devices are generally designed to handle large currents Answer: false โ For troubleshooting purposes, it is better to use a schematic diagram; instead of awiring diagram. Answer: true โ One of the most used symbols in control schematics is the ________. Answer: push button โ Mechanically held relays are energy-saving devices because the coils are energized only momentarily and not continuously. Answer: true โ Timers that can be set for multiple functions oras off-delay timers generally plug into ____-pin tube sockets Answer: 11 โ Normally open switches are drawn with the movable contact above and touching the stationary contact Answer: false
โ When configuring separate control wiring, the maintenance technician must ensure that the proper connections are made. Answer: true โ Line diagrams include all of the devices in the system and show the physical relationships between the devices. Answer: false โ Nontimed contacts are controlled directly by thetimer coil, as in a(n) ____ control relay. Answer: general-purpose โ When a jogging circuit is used, the machine operator has ____ control of the motor drive. Answer: instantaneous โ Sirens, horns, and loud buzzers may be used in production systems to call attention to malfunctions Answer: true โ What are the advantages of a mechanically held relay? Answer: The current is not continually applied to the coils of the relay, thus conserving energy. b. It is absolutely quiet in operation. c. The relay need not be reset when the power returns. d. The circuit continuity is maintained during a power failure. e. All of the above.(Correct Answer)
